<!doctype html>
<script src="../../resources/ahem.js"></script>
<style>
.sample {
    font: 10px/15px Ahem;
    letter-spacing: 20px;
}
</style>
<div class="sample" id="target1"><span href="#">abc</span> def</div>
<div class="sample" id="target2"><span href="#">abc</span> def</div>
<script>
for (let i = 0; i < 2; ++i) {
    document.body.offsetHeight;
    target1.firstChild.firstChild.appendData('X');
    target2.lastChild.insertData(2, 'X');
}
</script>
